WO2008031237A1

WO2008031237A1 - Injection device comprising an improved delivery element

Info

Publication number: WO2008031237A1
Application number: PCT/CH2007/000241
Authority: WO
Inventors: Philippe Kohlbrenner; Peter Stettler; Patrick Hostettler; Juergen Wittmann; Martin Wittwer
Original assignee: Tecpharma Licensing Ag
Priority date: 2006-09-15
Filing date: 2007-05-11
Publication date: 2008-03-20
Also published as: US20120197213A1; EP2076303B1; US8491538B2; CN101594896A; US8834431B2; US20090254044A1; PL2076303T3; WO2008031239A1; US20190247587A1; US11458257B2; US20090247960A1; JP2010503433A; HUE053543T2; EP2077878B1; WO2008031235A1; DK2076303T3; EP2077878A1; CN101563123B; JP2010503434A; CN101563123A

Abstract

The invention relates to an injection device, the delivery element (90) of which has an inner thread. Alternatively or in addition, the delivery element that is driven by rotation has a cylindrical outer wall region which is substantially smooth. Both features permit a delivery element to be designed that is less intimidating to patients than known threaded rods and facilitate easy cleaning. Preferably, the delivery element is non-rotatably guided and axially spring-loaded and can be inserted axially into the housing when the reservoir is replaced. The driving thread element (180) for the delivery element is preferably mounted in the vicinity of the distal end of the housing (20).

Description

Iniektionsqerät with improved conveying element

Technical area

The present invention relates to a device for administering a fluid product. The device may be designed as an injection device for injecting an adjustable dose of the product and in particular in the form of an injection pen, i. of a compact pen-shaped injection device.

State of the art

The prior art discloses a large number of injection devices for metered administration of medicaments, such as insulin, growth hormones or osteoporosis preparations, which have to be administered regularly. On the one hand, such devices should reliably and precisely dispense a presettable dose. On the other hand, they should be highly user-friendly and user-friendly. This is even more so since they are usually operated by the patient himself.

The drug can be accommodated in a replaceable carpule which can be inserted into a carpule holder. This can then be attached to a housing of the injection device, for example by a screw or a bayonet connection. To dispense a product plug in the carpule is advanced by a conveyor with a conveying element in the form of a piston rod. In particular, compact pen-shaped administration devices are known in which the distribution takes place automatically after a first triggering ("power-assisted pens"). The dose is usually preset in such devices by a rotation on a Dosierknopf. The device has a drive, eg a spring drive, which is tensioned when setting the dose. The device is triggered by pressing in a triggering device, which may be identical to the dosing button. In this case, the drive generates a drive movement, for example in the form of a rotational movement, which is converted into a propulsion movement of the piston rod in a distal direction. In the case of a drive by a rotary movement, the piston rod is usually formed as a threaded rod on which a drive nut runs.

DE-A 10 2004 063 644, DE-A 10 2004 063 647, WO-A 2004/002556 and DE-A 102 29 122 disclose such injection pens which represent general state of the art for the present invention.

EP-A 1 681 070 discloses in FIGS. 7A and 7B a manually driven injection pen whose piston rod 30 is hollow and has an internal thread instead of an external thread. This internal thread is in engagement with the external thread of a rotatable drive shaft 31, which is mounted in the region of its proximal end with respect to an inner housing part 13. The piston rod has on its outer side continuous longitudinal grooves, engage in the projections of a Fixierbuchse 32. This Fixierbuchse is set relative to the housing when a container holder 1 is connected to the housing, and can rotate freely when the container holder is detached from the housing. When a dose is administered, the drive shaft rotates, thereby pushing the piston rod, which is guided in a rotationally fixed manner via the fixing bush, linearly forward. When a reservoir is replaced, the container holder is released from the housing. As a result, the fixing bush and with it also the piston rod relative to the housing is freely rotatable. When the piston rod is now pushed back into the housing, the drive shaft remains stationary, and the piston rod ge performs a screw movement.

This device is capable of improvement in several ways. Thus, the screw movement of the piston rod upon insertion compulsorily requires that at its distal end a cap is rotatably mounted, which does not rotate with the piston rod during insertion, otherwise there would be no suitable non-rotatable mating surface available when inserted, at which the axial force required for insertion could attack. Furthermore, the presence of the Fixierbuchse requires that longitudinal grooves are formed on the outside of the piston rod. In these dirt can accumulate. Moreover, it is disadvantageous to support the drive shaft relative to the housing in its proximal end area, since a large area is required for this in a region in which otherwise e.g. Drive components could be accommodated. Finally, it is not ensured in this device that the piston rod actually touches the stopper of the drug reservoir.

Presentation of the invention

It is therefore an object of the present invention to provide an administering device which at least partially overcomes these disadvantages.

These objects are achieved by a device having the features of claim 1 or claim 12. Advantageous developments are specified in the dependent claims.

According to a first aspect of the present invention, there is provided a device for administering a fluid product comprising a housing and a conveying element for conveying the product from a reservoir. The conveying element is movable relative to the housing along a feed axis. Instead of an external thread, the conveying element has an internal thread whose threaded axis extends along the feed axis. This makes the thread used for the drive virtually invisible to the user, and it a largely arbitrary, adapted to the needs of the user and other technical requirements design of the outside of the conveyor element is possible. In addition, a particularly compact arrangement is possible. The device also has a drive device and a threaded element with an external thread which engages with the internal thread and can be fixed relative to the housing along the feed axis and can be displaced by the drive device into a rotational movement about the feed axis, around the feed element along the feed axis advance.

The conveyor element is, unlike the prior art, at all times rotatably guided relative to the housing, so performs both in the advancing movement for ejecting the product as well as the pushing back in the context of a container change a purely linear feed motion.

The threaded element is preferably designed as an external threaded rod, and the conveying element preferably has only in the region of its proximal end a short compared to the external thread of the threaded element internal thread in order to minimize friction losses.

The conveying element may in particular in a distal direction, i. the direction in which the feed takes place, be spring loaded. The spring serving for it is preferably so weak that it does not cause expulsion of the product from the reservoir. On the contrary, it serves to bring the conveying element automatically into its distal end position during a reservoir change, ie to extend it completely when the reservoir is removed from the housing. In this way it is ensured that the conveying element touches the reservoir plug at any time. The corresponding spring is preferably accommodated in the interior of the threaded element, which is designed for this purpose as a hollow spindle. It is preferably designed as a helical spring and guided on a guide needle.

In a preferred embodiment, the device also has a from Housing detachable container holder for holding the reservoir with the product. In a state in which the container holder is detached from the housing, the threaded element is then preferably rotatable relative to the housing such that the conveying element can be pushed into the housing in this state by a purely axial displacement in the proximal direction. In this case, the threaded element rotates due to the threaded engagement with the conveying element.

In a preferred embodiment, the conveying element is surrounded radially at least partially by a guide sleeve having a proximal and a distal end. The length of this guide sleeve preferably corresponds to at least the maximum feed area of the conveyor element, i. the distance between the distal and the proximal end position of the conveying element. Near its distal end, the guide sleeve is rotatably connected at least during administration with the housing or a housing-fixed element. The conveyor element is rotatably guided along the feed direction in the guide sleeve. Preferably, the conveying element is at least in the region of its proximal end with the interior of the guide sleeve in a rotationally fixed engagement, but allows an axial displacement. For this purpose, in the region of the proximal end, an engagement structure projecting radially outwardly from the outer circumferential surface of the conveying element, e.g. in the form of a plurality of longitudinal ribs, formed with a complementary structure, e.g. in the form of a plurality of longitudinal grooves, cooperating on the inner peripheral surface of the guide sleeve. The device then preferably also comprises an outer sleeve with a proximal and a distal end, which in turn at least partially radially surrounds the guide sleeve. Near its proximal end, this outer sleeve is connected to the rotatable element. Near its distal end, the outer sleeve is rotatable and guided displaced relative to the guide sleeve.

The considerations on which this embodiment is based can be summarized as follows: The conveying element is intended to be movable relative to the stationary gear. housing be secured against rotation and longitudinally guided. In this case, the conveying element should preferably be designed on its outside substantially smooth or otherwise arbitrary. This implies that the conveying element is longitudinally guided only in the region of its proximal end in a rotationally fixed to the housing element. However, this in turn requires that this non-rotatable element is at least as long that the guide is ensured over the entire range of the feed of the conveying element. To ensure this, a sleeve-like structure of the non-rotatable element is selected, which is therefore referred to as a guide sleeve, with a length of this guide sleeve, which corresponds at least to the feed region of the conveyor element. To drive the conveying element, the rotatable element must furthermore be arranged in the interior of the conveying element. In order to ensure a threaded engagement over the entire feed area, the rotatable element must extend at least over a length from proximal to distal in the conveying element, which corresponds to the feed area. The only available access to the rotatable element consists of the proximal end. A drive of the rotatable element must therefore take place via its proximal end. At the same time, the rotatable element must be supported in any way relative to a housing-fixed element. This bearing must be able to absorb axial forces, as axial forces are transmitted from the conveyor element via the threaded engagement with the rotatable element. Although a storage could be provided directly at the proximal end of the rotatable element. However, this would take up a lot of space in an area that should be available for other tasks if possible. It is therefore desirable to move the location of storage to another location, as close as possible to one of the ends of the housing. This is done here with the help of the outer sleeve, which is firmly connected to the rotatable element and this quasi continues along the outside of the guide sleeve to the distal direction. The storage then takes place between the outer sleeve and the guide sleeve, in the region of the distal end of the outer sleeve. As a result, a very compact unit is created, whose radially relatively much space-consuming storage to lie in a proximal region comes where it only slightly disturbs, and which makes it possible to accommodate in the radial gap between the outer sleeve and the housing further elements of the injection device. Furthermore, the fact that the outer sleeve (and thus ultimately the rotatable element) is mounted on the guide sleeve and not on the housing itself, that the entire unit of guide sleeve, outer sleeve, bearing, rotatable member and conveying element relative to the Housing specifically designed to be movable, for example in the context of a container change.

According to a second aspect of the present invention, a device for administering a fluid product comprises a housing and a conveying element for conveying the product from a reservoir. The conveying element is movable relative to the housing along a feed axis between a proximal starting position and a distal end position and preferably guided in a rotationally fixed manner. It protrudes through a passage opening in a boundary wall of the housing. Furthermore, a drive device for generating a rotational movement of a rotatable element relative to the housing is present, wherein the rotatable element is coupled to the conveying element such that the rotational movement causes a feed movement of the conveying element along the feed axis. The conveying element has a substantially smooth outer wall region whose length corresponds at least to the distance between the distal end position and the proximal starting position. In this way it is possible to arrange the conveying element so that during the advance only the smooth outer wall region is advanced through the opening in the housing wall. Thus, it can be avoided that the user gets to see an external thread that could have a deterrent effect on him or that could be difficult to clean.

A "substantially smooth" outer wall region is understood in particular to mean a region of the outer circumferential surface of the conveying element which has no technically conditioned structures which lead to insufficient absorption. could lead to entanglement by the user or could make cleaning more difficult. On the other hand, however, the outer wall area may well have fine structures, for example a microstructure or nanostructuring. Distinct from the smooth outer wall region, for example, may be a structure which is designed to advance a plug in the product container, for example a feed flange protruding radially beyond the outer wall region. By contrast, the region arranged proximally from the outer wall region is normally located permanently inside the housing and is thus invisible to the user. This proximal region can therefore be configured as desired within the scope of the technical requirements.

If the feeding of the conveying element is to take place via an external thread on which a drive nut runs in a conventional manner, this external thread will typically connect proximally to the smooth outer wall region.

In an advantageous embodiment, the conveying element with respect to the housing or a housing-fixed element is liquid-tight, at least splash-proof, sealed. This effectively prevents the penetration of liquids.

A corresponding seal may be formed directly between the conveyor element and the housing. But it is also conceivable that a first seal between the conveying element and a member which is movable relative to the housing, is formed, and a second seal between the movable member and the housing is formed. The movable element may e.g. be arranged so that it is movable only during a change of the reservoir and is immobile during the actual administration to the housing. It may in particular be sleeve-shaped.

A substantially smooth, cylindrical, preferably circular-cylindrical outer wall region of at least one annular sealing element is preferred surround. In this way, a simple and efficient sealing can be achieved, as is not possible with the piston rods with external thread of the prior art. The length of the substantially smooth outer wall region corresponds at least to the distance between the distal end position and the proximal starting position, between which the conveying element is movable during the course of administration in order to ensure a seal over this entire region. The outer wall region may have fine structures, in particular in the region below 100 micrometers, preferably below 10 micrometers, which are suitable for at least not impairing or even improving the sealing effect, for example a microstructure or nanostructuring. These structures may have a preferred direction to inhibit the flow of liquids.

The at least one annular sealing element preferably comprises at least one circumferential, flexible sealing lip, which rests on the cylindrical outer wall region and acts as a wiper in the manner of a windshield wiper. The contact angle between the sealing lip and the outer wall region is preferably less than 90 degrees. It may, however, be e.g. also be designed as a ring with a round or polygonal cross-section.

Preferably, the interior of the housing is completely sealed liquid-tight against the outside of the housing, so not only in the area in which the conveying element is guided to the outside, but also in other areas, e.g. in the range of moving dosing or actuating elements.

The conveying element or a sealingly cooperating element may in particular consist of a hydrophobic material or be hydrophobic coated in order to achieve or improve a sealing effect by avoiding capillary creep.

The reservoir is preferably held in a container holder, which is releasably attachable to the housing. When fastening, this is preferably such guided relative to the housing, that it relative to the housing performs a combined rotational movement about an axis of rotation and translational movement along the axis of rotation. The device then preferably further comprises a spring element and a latching element. These elements are arranged such that the spring element generates a spring force acting essentially along the axis of rotation on the latching element. The latching element thereby causes in a predetermined holding position of the container holder a releasable latching connection, by which the container holder is fixed relative to the housing. For this purpose, for example, protrude into the projection of the locking element in a recess of the Behnish holder or a non-rotatable element. A reverse arrangement is conceivable. The latching connection is preferably designed so that it is by a movement of the container holder relative to the housing, which is opposite to the movement during fastening, detachable again, ie, the latching connection need not be unlocked manually.

It is therefore preferably provided a connection in the manner of a screw or preferably bayonet connection between the container holder and the housing or between them connected to these elements. In conventional bayonet connections between two elements, an element with a bayonet pin in a suitably shaped slot or in a corresponding groove in the manner of a gate guide of the other element is usually performed until the bayonet pin reaches an end position (corresponding to the holding position). In such compounds, there is the problem of avoiding unintentional sliding back of the pin from the end position out. A similar problem arises with screw connections which are fixed by a clamping force and can likewise be released inadvertently. The present embodiment solves this problem by providing an axially spring loaded (and axially movable) detent member. Such a locking element ensures a defined fixation of the container holder in the holding position, without the risk of unintentional release exists. The connection is only solvable by overcoming a sufficiently large force. This wear, which could lead to a leaching of the connection, avoided. By the latching element is spring-loaded in the axial direction, a simple and space-saving design of the locking element and the spring element is made possible.

As a rule, the container will be a container with a cylindrical wall region and a stopper displaceable therein, a so-called carpule, which defines a longitudinal direction and is accommodated in a container holder with a correspondingly elongate shape. When mounting on the housing, the container holder is preferably rotated about this longitudinal direction, that is, the axis of rotation coincides with the longitudinal axis. For administration of the product, the plug is advanced by the conveyor element along the longitudinal direction. More generally, thus preferably, the feed direction of the conveying element corresponds to a direction along the axis of rotation about which the container holder is rotated during its attachment.

There are various possibilities for the arrangement of the spring and latching element. According to a preferred embodiment, the locking element is rotatably relative to the housing and releasably locked in the locking position with an element which is rotationally fixed relative to the container holder. In other words, the locking element does not follow the rotation of the container holder, but remains in the attachment of the container holder rotationally fixed to the housing. However, the reverse arrangement is conceivable in which the locking element is rotatably relative to the container holder.

In a preferred embodiment, the device comprises a driving element, which is arranged rotatably relative to the housing. The entrainment element is guided relative to the housing in such a way that it is entrained by the container holder when the container holder is fastened to the housing and when the container holder is detached from the housing, and is set in motion which comprises a rotational movement about the axis of rotation. The locking element then causes in the holding position of the container holder a releasable latching connection, by which the driving element is fixed relative to the housing. This then again holds the container holder. The container holder is thus fixed indirectly, via the driving element, relative to the housing. This allows a greater freedom in the design of the container holder and the locking element and spring element.

In an advantageous embodiment, the device comprises a relative to the housing rotatably arranged guide element, which may be formed in particular as a guide sleeve. This guide member may be rigidly connected to the housing, in particular be made in one piece with this, or it may be axially displaceable relative to the housing. The driving element, which can also be configured as a sleeve and can then be referred to as a bayonet sleeve, is at least rotatably connected to the guide element. The spring element and the latching element are preferably arranged rotationally fixed relative to the guide element, and the latching element is releasably latched in the holding position of the container holder with the driving element. In particular, the guide element relative to the housing axially displaceable and the driving element, although rotatably, but be connected axially fixedly fixed to the guide element. This design makes it possible that further arranged in the housing parts of the device, which are connected to the guide element, are axially displaced when the container holder is attached to the housing. Thereby, the administering device can be automatically released upon detachment of the container holder, e.g. reset and brought back to a ready to use state when attaching the container holder. In particular, it is possible in this way, when releasing the container holder the interior of the device (in particular the drive means and optionally a triggering device connected thereto) to move in a distal direction, that the triggering device, which can be configured as a push button, fed into the housing indicating that the device is not ready for use.

In this case, the carrier element is preferably guided relative to the housing in such a way that, when the container holder is fastened to the housing, it is prevented from being caught by the container. nishalter taken and offset relative to the housing in a combined rotational movement about the axis of rotation and translational movement along the axis of rotation in a proximal direction.

Preferably, the driving element between two defined end positions is movable, and the locking element causes in both positions a releasable locking connection, by which the driving element is fixed relative to the housing. In this case, the driving element assumes its first end position when the container holder assumes its holding position, and it assumes its second end position when the container holder is removed from the housing. Preferably, the latching element is releasably latched in both the first end position and in the second end position directly to the driving element.

The entrainment element is preferably in at least one guide slot relative to the housing, i. on the actual housing itself or on a housing-fixed element, guided, in particular by one or more corresponding pin. Likewise, the container holder when mounting on the housing in at least one guide slot, guided in the manner of a bayonet connection, relative to the housing.

The latching element is preferably designed in the form of a ring which extends around the axis of rotation and in particular around the feed element. On the ring suitable locking lugs may be formed. This locking element can be axially spring-loaded by a separate spring element. This may be e.g. to act on a pressure loaded coil spring or other type of elastic element. Preferably, however, the spring element has the form of a ring which extends around the axis of rotation and is curved about an axis perpendicular to the axis of rotation, so that the spring force is generated by compressing the spring element along the axis of rotation.

Preferably, the locking element is formed integrally with the spring element. This leads to a particularly simple embodiment. In particular, the locking element may be formed as a projecting in the direction of the axis of rotation projection on the spring element. This is particularly advantageous if the spring element, as described above, has the shape of a curved ring.

The device may further comprise at least one ball bearing which absorbs forces transmitted between the conveying element and the housing. By providing a ball bearing, frictional losses caused during administration due to the transfer of forces between the impeller and the housing are substantially minimized.

A ball bearing is particularly advantageous if the device comprises at least one rotatable element cooperating with the conveying element and a drive device for generating a rotational movement of the rotatable element relative to the housing, wherein the rotational movement of the rotatable element along a (preferably linear) advancing movement of the conveying element along a feed axis in a distal direction, preferably by a threaded engagement, which is preferably non-blocking. In this case, the ball bearing is advantageously arranged such that it receives along the feed axis acting (axial) forces, which are transmitted from the (preferably non-rotatable) relative to the housing conveying element on the rotatable element on the housing, ie between the rotatable EIe- ment and the housing act. Expressed in general terms, therefore, axial forces acting in particular in the proximal direction are transmitted between the conveying element and the housing via a rotatable connection which is displaceable in the axial direction. In the prior art, a sliding connection between the rotatable element and the housing or a housing-fixed element is usually provided for this purpose. In the present embodiment, however, at least one ball bearing is provided, which is preferably between the rotatable member or an associated Element on the one hand and the housing or a housing-fixed at least during the administration element on the other hand. As a result, friction losses during rotation of the rotatable element can be avoided.

Preferably there are two ball bearings which are preferably arranged to provide forces along the feed axis both in a proximal direction and in the opposite distal direction, i. the direction in which the feed takes place can record. Axial forces in the proximal direction usually arise during administration, while axial forces in the distal direction can arise, in particular, when the delivery element is spring-loaded in the distal direction, as is the case in a preferred embodiment. The spring serving for this purpose is preferably so weak that it does not cause expulsion of the product from the reservoir. Rather, it serves to automatically bring the conveying element into its distal end position during a reservoir change, ie to extend it completely when the reservoir is removed from the housing. If the conveyor element is in communication with the rotatable element, this will result in the rotatable element being set in rotation when the conveyor element extends due to the spring force. In order to keep the necessary spring force small, a ball bearing is of particular advantage, since it minimizes the frictional forces acting during the extension of the conveying element.

Brief description of the drawings

Preferred embodiments of the invention will now be described with reference to the drawings, in which:

1 is an exploded perspective view of an injection device according to a first embodiment; FIG. 2 shows a longitudinal section through the injection device of FIG. 1; FIG.

FIG. 3 shows an enlarged detail from FIG. 2; FIG.

4 shows a longitudinal section through an arrangement of a guide sleeve and a coupling sleeve in the injection device of Fig. 1; Fig. 5A is a plan view of a ball bearing ring; Fig. 5B is a sectional view of the ball bearing ring in the plane A - A; Fig. 6 is a perspective view of a coupling sleeve; Fig. 7 is a longitudinal section through selected parts of the injection device of Figure 1;

8 is a perspective view of a bayonet sleeve;

Fig. 9A is a plan view of a bayonet spring; Fig. 9B is a side view of the bayonet spring of Fig. 9A; Fig. 9C is a perspective view of the bayonet spring of Fig. 9A;

FIG. 10 shows a longitudinal section through selected parts of the injection device of FIG. 1; FIG. 11A is a longitudinal section through selected parts of the injection device of Figure 1 with a dose-limiting ring in its end position ..; FIG. 11B shows a longitudinal section through selected parts of the injection device of FIG. 1 with the dose-limiting ring in its initial position; FIG.

Fig. 12A is a perspective view of a coupling shaft with a dose limiting ring of the injection device of Fig. 1;

FIG. 12B shows the parts of FIG. 12A in an exploded view; FIG.

12C shows the coupling shaft of FIG. 12A in a perspective view from another viewing direction;

Figure 13 is an exploded view of a locking sleeve, a clutch spring and a support ring.

Fig. 14 is a perspective view of selected parts of the injection apparatus of Fig. 1;

15 is an exploded perspective view of the proximal end of the

Injection device of Fig. 1;

16 shows a longitudinal section through the injection device of Fig. 1 in the

Starting position;

17 shows the longitudinal section of FIG. 16 after a first metering up at half the maximum dose;

FIG. 18 shows the longitudinal section of FIG. 16 after a first metering up to the full maximum dose; FIG.

FIG. 19 shows the longitudinal section of FIG. 16 after a first triggering and a second metering; FIG.

FIG. 20 shows a longitudinal section through the injection device of FIG. 1 after complete emptying of the carpule; FIG.

Fig. 21 is a longitudinal section through an injection device according to a second

Embodiment.

Detailed description of preferred embodiments

The basic structure and the basic operation of an injection device according to the invention will first be explained below with reference to FIGS. 1 and 2 before the construction of the device and the mode of operation of the metering mechanism are explained in detail with reference to FIGS. 3 to 20 for a first embodiment. A second embodiment will be discussed with reference to FIG. 21.

Basic structure and operation

Fig. 1 shows an injection device in the form of an injection pene in a perspective exploded view. Fig. 2 shows the device in longitudinal section. The following description refers to the apparatus in the assembled state as shown in FIG.

The injection device has a housing sleeve 20, in which a mechanism for

Setting and pouring a dose is housed. The housing sleeve 20 is substantially circular cylindrical in shape and thereby defines a longitudinal axis. A bayonet connection described in more detail below is a container. holder in the form of a cartridge sleeve 30 at a distal end of the housing sleeve 20 releasably secured. This takes a container in the form of a carpule 40 with a liquid drug in which a plug 41 is slidably guided. This limits a drug reservoir R of variable volume within the carpule. Instead of a carpule, another container may be present, whose volume is variable, for example, a container with concertina-like folded walls in the manner of a bellows. By an elongated viewing window 34 in the cartridge case 30, the contents of the carpule 40 can be controlled. At the distal end of the cartridge case 30, a needle holder 31 is screwed, which carries a hollow needle (cannula) 32 serving as an injection needle, the proximal end of which projects through a sealing septum into the medication reservoir R. A peelable needle shield 33 surrounds the forwardly projecting portion of the needle 32 and protects a user from accidental puncturing. A protective sleeve 10, whose distal end is permanently closed with a protective cap 50, is pushed over the cartridge sleeve 30. Inside the protective sleeve 10, a retaining ring 11 is mounted with locking arms 12 extending in the proximal direction. The ends of the latching arms 12 are releasably latched to the cartridge sleeve 30. While the invention is explained herein with reference to an injection device having a needle 32, it is also conceivable that the injection device has a plurality of needles or no needle as in a jet injector.

At the proximal end of the housing sleeve 20, a metering sleeve 60 is rotatably disposed therein with a push button 80. The dosing sleeve serves to set a dose to be dispensed from the medicament reservoir R and to tension a drive device with a drive element in the form of a diagrammatically indicated only, acting as a torsion spring coil spring 310. The set dose is displayed on a display drum 70 and can through a window 21 in the Housing sleeve 20 are read, which is covered by a transparent cover 22. Correcting (reducing) the set dose is possible in a simple manner by turning back the dosing sleeve 60. Below, with reference to the further figures, Explain in more detail how this setting is made possible.

With reference to these parts, the following directions can be defined, to which reference will be made in the following: The distal direction is the direction in which the administration takes place, i. it points along the longitudinal axis of the push button 80 in the direction of the hollow needle 32. The proximal direction is defined accordingly as the opposite direction. If reference is made to a direction of rotation (clockwise, counterclockwise), this refers to the direction of rotation that is perceived when looking along the longitudinal axis in the distal direction.

After setting the dose, the hollow needle 32 is pierced through the skin of the patient, and it is triggered a dose distribution by the user presses the push button 80 into the dosing sleeve 60. By a mechanism described in detail below, a rotational movement is generated by the drive means, which is converted into a propulsion of a conveying element in the form of a feed sleeve 90 in the distal direction. The feed sleeve 90 pushes the stopper 41 of the medicament bobbin 40 in the distal direction over the set amount by means of a feed flange 100 arranged at its distal end, whereby the release of the medicament from the reservoir R is effected. The feed sleeve 90 thus acts as a piston rod for the piston formed by the feed flange 100 and the plug 41. After the end of the administration, the user releases the push button 80 again. The display drum is entrained during the advance of the feed sleeve 90 of the drive device such that it returns to its zero position in the course of the distribution. Thus, the injection pen is immediately ready for the next dose setting.

If the drug is in the drug reservoir R is running low, so the feed sleeve 90 is almost completely extended, this is detected by a dose limiting device described in detail below in the Injektionspen. The dose limiting device then allows the user to lent to adjust a maximum of the remaining available residual dose. During a subsequent change of carpule, the dose limiting device as well as the display drum 70 automatically return to the initial state. So no manual reset is required.

The structure and mode of operation of the mechanics are described in detail below.

Structure of the mechanics

FIG. 3 shows an enlarged view of the rear (proximal) region of the injection device of FIG. 1. The structure of this region will now be described in detail, essentially from the inside to the outside.

The feed sleeve 90 is rotatably and rotatably mounted in a longitudinal direction in a rotatably and slidably disposed to the housing guide sleeve 110 again. For this purpose, the feed sleeve 90 has at its proximal end a plurality of radially outwardly projecting guide cam 91, which are guided in complementary longitudinal grooves on the inside of the guide sleeve 110.

The guide sleeve 110 is particularly well visible in the Fig. 4, which illustrates the interaction of the guide sleeve with other parts. The guide sleeve 110 has at its distal end a radially outwardly projecting, circumferential annular flange 111 with radial bores 112. An annular bearing holder 130 is pushed from the proximal side over the guide sleeve 110, surrounds the annular flange 111 radially and is rigidly connected to the drawing via radial dowel pins.

A coupling sleeve 120 is rotatably supported between the annular flange 111 of the guide sleeve 110 and an inwardly projecting shoulder 132 of the bearing holder 130. As will be described in more detail below, the coupling sleeve 120 is is connected via a threaded rod 180 with the feed sleeve 90 and therefore forms part of a conveyor, which is driven by a rotational movement and causes a feed of the conveying element in the form of the feed sleeve. The coupling sleeve 120 therefore absorbs considerable axial forces during operation, which are transmitted via their bearing to the guide sleeve 110, the bearing holder 130, the mechanism holder 150 and thus ultimately to the housing.

In order to make storage as low-loss as possible, the storage takes place via ball bearings. For this purpose, a first ball bearing ring 140 is provided between the flange 111 of the guide sleeve and a radially circumferential flange 124 of the coupling sleeve 120. Another such ball bearing ring 140 is disposed between the flange 124 and an end face of the bearing holder 130.

The ball bearing ring 140 is shown in detail in FIGS. 5A and 5B. He carries a plurality of bearing balls 141 (here twelve pieces). These run, as can be seen in Fig. 3, in flat, circular grooves which are formed in both end faces of the radial flange 124 of the coupling sleeve 120, in the corresponding end face of the flange 111 of the guide sleeve 110 and in the end face of the bearing holder 130.

The coupling sleeve 120 is shown together with the ball bearing rings 140 (but without balls 141) in FIG. 6. As can be seen particularly well here, a plurality of longitudinal ribs 122 are formed on the cylindrical sleeve body 121, which extend over a considerable part of the length of the sleeve body in the longitudinal direction up to its proximal end. In between there are corresponding grooves. A thickening 123 is followed by the flange 124, which adjoins the ball bearing rings 140 on both sides.

In Fig. 7 it is shown how the unit of guide sleeve 110 and bearing holder 130 in a sleeve-shaped mechanism holder 150 rotationally fixed, but is held displaceable in the longitudinal direction. The mechanism holder 150 has a distal portion 151 with an enlarged inner and outer diameter and a proximal portion 152 with a slightly smaller inner and outer diameter. These two sections are connected by a step 153. The outside of the distal portion 151 is held rigidly in the housing sleeve 20. Thus, therefore, the entire mechanism holder 150 relative to the housing immovable, so functionally forms part of the housing.

Adjacent to the step 153, at least two longitudinal slots 154 are formed in the mechanism holder 150. In the bearing holder 130 pins are used, which are not shown in Fig. 7. These protrude radially beyond the bearing holder 130 and into the longitudinal slots 154 of the mechanism holder. As a result, the bearing holder 130 and the guide sleeve 110 fixedly connected thereto are displaceably guided in the longitudinal direction between a distal and a proximal end position and secured against rotation in the mechanism holder 150. Towards the proximal end, an external thread 157 is formed on the outer lateral surface of the mechanism holder 150. On the inner surface a plurality of longitudinal grooves 158 are formed in this area.

In the distal direction, a bayonet sleeve 160 adjoins the guide sleeve 110 and the bearing holder 130, which is also shown in FIG. 8. It is held on the bearing holder 130 in the axial direction and rotatable relative thereto. With an inwardly projecting annular flange 161, it supports the unit consisting of guide sleeve 110 and bearing holder 130 with coupling sleeve 120 held therein in the distal direction. The bayonet sleeve 160 has two axially projecting in the distal direction and diametrically opposite arms 162 having radial openings 163. In these openings radially outwardly projecting pins are used, which run in two as slide guides (positive guides) acting guide slots 155 of the mechanism holder 150. These guide slots 155 are designed such that the bayonet sleeve 160 is rotated in a counterclockwise direction (in the sense of the above-mentioned). NEN definition, ie when viewed along the longitudinal axis in the distal direction) is forced to move axially in the proximal direction. In this way, the unit of guide sleeve 110, bearing holder 130 and coupling sleeve 120 is displaced in the proximal direction. Conversely, upon rotation of the bayonet sleeve 160, this unit will move clockwise in the distal direction. Parallel to the guide slots 155 another pair of guide slots 156 extends to receive radial pins 36 of a locking portion 35 of the cartridge case 30 (see Figures 1 and 3). When inserting the cartridge case 30 into the housing, therefore, the cartridge tube is subject to a forced guidance, so that the cartridge case 30 performs a combined rotational movement and displacement. The cartridge case 30 is designed so that it is coupled in its movement with the arms 162 of the bayonet sleeve 160 and the bayonet sleeve 160 entrains.

The guide slots 155 are of finite length and limit the movement of the bayonet sleeve between a distal and a proximal end position. In Fig. 7, the proximal end position is shown. In particular, the guide slots 155 allow the bayonet sleeve to rotate 90 degrees between these positions.

In order to releasably rotatably fix the bayonet sleeve in its two end positions relative to the guide sleeve 110 and thus to fix relative to the housing sleeve 20, a bayonet spring 170 is arranged between the bayonet sleeve 160 and the guide sleeve 110. This is shown in detail in FIGS. 9A to 9C. The bayonet spring 170 has a substantially flat and annular basic body 171 acting as a spring element. For this basic body protrude two diametrically opposite, axially flat projecting protrusions or projections 172 as locking elements or locking cams axially in the distal direction. Two diametrically opposite flat tongues 173 protrude inwards and come to lie in corresponding flat recesses of the guide sleeve 110. As a result, the bayonet spring 170 is held against rotation on the guide sleeve 110. As can be seen from Fig. 9B, is the Base body 171 is slightly bent about an axis perpendicular to the longitudinal axis, in such a way that the center of curvature is on the same side of the bayonet spring as the projections 172 (ie distal). As a result, the bayonet spring 170 between the guide sleeve 110 and the bayonet sleeve 160 is permanently biased such that the projections 172 are pressed in the distal direction against the corresponding counter surface on the annular flange 161. In this counter surface four recesses are present, which are arranged at intervals of 90 degrees about the longitudinal axis. In the proximal end position, the projections 172 come to lie in a first pair of these recesses, while in the distal end position, in which the bayonet sleeve is rotated by 90 degrees, they are received in the second pair of recesses. As a result, there are two defined locking positions in which the bayonet sleeve 160 via the bayonet spring 170 with the projections 172 releasably locked to the guide sleeve 110. In both positions, a certain force must first be overcome in order to move the bayonet sleeve again in the direction of the respective other end position. The recesses may be differently pronounced, for example, be different deep, so that in the two detent positions a different release force is required.

In one detent position, the carpule sleeve 30 is rotationally and non-displaceably held on the guide sleeve 110 and thus ultimately on the housing via its coupling with the bayonet sleeve 160. In the other detent position, the carpule sleeve 30 is released from the housing. The bayonet sleeve 160 is in turn locked in this position with the guide sleeve 110 and thereby fixed to the housing 20 rotationally and non-displaceably. In this way, it is ensured that the cartridge tube when inserted into the guide slots 156, the arms 162 of the bayonet sleeve again in the correct position about the longitudinal axis "finds" and then can take them after releasing the locking connection.

In the present example, the locking elements are formed as projections 172 integral with the spring element in the form of the base body 171. Instead, but also a separate locking element, for example in the form of a rigid ring be provided with locking cams, which is pressed by the spring element in the axial direction. Instead of projections, the latching element can also have depressions which then interact with corresponding projections of the counter-surface. In the present example, the locking element is rotationally fixed to the housing. Instead, it can also be rotationally fixed to the bayonet sleeve. The spring element can also be designed differently for generating an axial force. So there are multiple modifications of the lock shown here between the cartridge case 30 and the housing possible.

FIG. 10 shows the parts of the injection device shown in FIG. 7 together with further components. In particular, the feed sleeve 90 is now inserted into the guide sleeve 110. At its proximal end, the feed sleeve 90 has a short internal thread 92, in which a hollow external threaded rod 180 is guided. This is connected at its proximal end via a transverse pin 181 rigidly connected to the coupling sleeve 120. A feed of the feed sleeve 90 in the distal direction is thus carried out by the coupling sleeve 120, which is indeed rotatably mounted, performs a rotational movement. Because of the rigid connection between coupling sleeve 120 and external threaded rod 180, this rotational movement also causes rotation of the externally threaded rod 180. The advancing sleeve 90, with its internal thread 92, runs on the external threaded rod 180, similar to a nut. The feed sleeve 90 is rotationally fixed relative to the guide sleeve 110, since it runs over the guide cam 91 in longitudinal grooves on the inside of the guide sleeve 110. In this way, the feed sleeve 90 is axially advanced upon rotation of the externally threaded rod 180. Overall, therefore, a rotational movement of the coupling sleeve 120 is converted into an axial displacement of the feed sleeve 90.

As can be seen from Fig. 3, the feed sleeve 90 is supported in this forward thrust movement by a long, loaded on pressure coil spring 190 which is disposed in the interior of the threaded rod 180 and on a

Guiding needle 200 is guided. The coil spring 190 presses an annular Thickening 201 near the distal end of the guide needle 200 in the distal direction against the feed flange 100. An axial pin 202 protrudes into a corresponding blind hole of the feed flange 100 and is rotatable in this blind hole.

Furthermore, in FIG. 10, a substantially cylindrical transmission sleeve 210, which partially surrounds the coupling sleeve 120, is inserted into the mechanism holder 150 from the proximal side. The transmission sleeve 210 has a plurality of longitudinal ribs 212 on the outside. The outer diameter of the transmission sleeve 210 is chosen so that it is freely rotatable in the interior of the mechanism holder 150 despite their outer longitudinal ribs. On the inside, the transmission sleeve 210 has an internal thread 211, in which a dose-limiting ring 220 runs with a corresponding external thread 221. In the interior of the dose-limiting ring 220, particularly clearly visible longitudinal grooves 222 are present in FIGS. 12A and 12B, in which the longitudinal ribs 122 of the coupling sleeve 120 (see FIG. As a result, the dose limiting ring 220 is on the one hand displaceable in the axial direction on the coupling sleeve, on the other hand guided in the internal thread of the transmission sleeve 210. A rotation of the coupling sleeve 120 relative to the transmission sleeve 210 thus leads to a rotation and axial displacement of the dose limiting ring 220th

The axial displacement range of the dose limiting ring is limited in the distal and in the proximal direction. This will be explained with reference to Figures 11 A, 11 B, 12A and 12B.

In FIGS. 11A and 11B, a coupling shaft 230 is connected to the transmission sleeve 210. The coupling shaft has an axis 231 with a transverse bore 232 near the proximal end 233. From the distal end of the axle, a circumferential flange 234 extends radially outward. From this, in turn, an annular flange 235 extends axially in the distal direction. The outer diameter of the flange 234 is greater than that of the Ring flange 235, whereby the flange 234 projects radially beyond the annular flange 235 and forms a stop for the transmission sleeve 210. The annular flange 235 is inserted into the transmission sleeve 210, so that it rests with its proximal end on the flange 234. The annular flange is secured by radial pins in the transmission sleeve 210, which are inserted into bores 237. As a result, the coupling shaft 230 and the transmission sleeve 210 are connected to one another in a torque-proof and non-displaced manner. In the inner surface of the annular flange 235 a plurality of longitudinal grooves 238 are formed.

Figures 12A and 12B show the coupling shaft 230 and the dose limiting ring 220 alone. At the dose-limiting ring 220, a radial stop 223 is formed, which cooperates with a corresponding radial stop 236 on the annular flange 235 of the coupling shaft. A radial stop is understood to mean a stop face whose surface normal essentially points in the tangential direction and which is designed to cooperate with a corresponding counter-surface. The radial stop is thus stressed primarily in the tangential direction (ie in the direction of rotation) instead of in the axial direction. As a result, a radial stop avoids the risk of jamming, which occurs when two parts axially collide with one another via a screw connection, and which is particularly pronounced with a small pitch of the screw thread. The radial stop 236 here limits the screw movement of the dose-limiting ring 220 in the proximal direction. In FIG. 11A, the dose-limiting ring 220 is shown in the resulting proximal end position, whereas FIG. 11B is shown in a distal starting position.

In an inwardly facing, chamfered in the distal direction annular flange 213 at the distal end of the transmission sleeve 210, the proximal end of a locking sleeve 280 is rotatably clicked. For better clarity, the locking sleeve 280 is not shown in FIG. However, it is shown in FIG. 13. The locking sleeve comprises an annular main body 281, from which four arms 282 extending in the distal direction in FIG extend the distal direction. The main body has on its inner surface longitudinal grooves 284 which are interlocked with the longitudinal ribs 122 of the coupling sleeve 120. As a result, the locking sleeve 280 is displaceable in the longitudinal direction relative to the coupling sleeve 120, but secured against rotation. At the end of the arms 282, inwardly extending flange portions 283 are provided. The possible displacement range is limited in the proximal direction by these flange areas. These abut in the proximal end position of the locking sleeve 280, as shown in FIG. 3, to the distal end of the longitudinal ribs 122 of the coupling sleeve 120. On the outer peripheral surface of the main body 281 longitudinal ribs are formed. These longitudinal ribs engage in the position of FIG. 3 in the inner longitudinal grooves 158 of the mechanism holder 150 a. As a result, the locking sleeve 280 is axially displaceable in this position relative to the mechanism holder 150, but secured against rotation. Ultimately, the locking sleeve 280 secures in this position so the coupling sleeve 120 against rotation in the mechanism holder 150. As will be explained below, however, the locking sleeve 280 is so far displaced in the distal direction that it can come out of engagement with the mechanism holder 150 and relative to this then rotatable together with the coupling sleeve 120.

The locking sleeve 280 is biased by a coupling spring 290 in the proximal direction. The clutch spring is in the form of a pressure-loaded coil spring, which surrounds the arms 282 of the locking sleeve 280 and rests with its proximal end on the distal end side of the main body 281. At the distal end of the clutch spring 290 this is held on a support ring 300 which abuts in the distal direction to the bearing holder 130 and on the inside of which longitudinal grooves are formed.

In FIG. 14, the unit of FIG. 10 is shown with yet further components. On the mechanism holder 150 now the previously mentioned display drum 70 is held. In addition, a stop sleeve 240 can be seen. As can be seen in Fig. 2, the stop sleeve 240 by pins which project into the recognizable in Fig. 14 radial holes 242, immovable with the Housing sleeve 20 connected. At its distal end radial stops 243 are formed. Their proximal end is serrated, ie teeth 244 are formed on the front side for a ratchet connection to be described.

The display drum 70 has an internal thread, which can be seen in FIG. This runs on the external thread 157 of the mechanism holder, which is particularly well recognizable in Figures 7 and 10. At its proximal end, the display drum 70 tapers to form an annular region 72. Longitudinal grooves are formed on the inner side of the annular region 72. With these longitudinal grooves, the display drum 70 is secured against rotation, but guided displaceably in the longitudinal direction on the longitudinal ribs 212 of the transmission sleeve 210. By combining this longitudinal guide on the transfer sleeve and the thread guide on the mechanism holder, rotation of the transfer sleeve 210 results in combined rotation and longitudinal displacement of the indicator drum 70. This movement is limited by radial stops in both directions. At the proximal end, a radial stop cooperates with the radial stop 243 of the stop sleeve 240. At the distal end, a corresponding radial stop 73 cooperates with a radial stop 159 of the mechanism holder 150. As a result, the screw movement of the display drum 70 is limited in both directions by radial stops.

In the following, the mechanism for setting a dose and triggering the administration of this dose will now be explained with reference to FIGS. 3 and 15. At the proximal end of the housing sleeve 20, the already mentioned dosing sleeve 60 is arranged. It is axially verschiebegesichert with a spring ring 61 and rotatably fixed to the stop sleeve 240. The dosing sleeve 60 is rotatable about the longitudinal axis of the housing sleeve 20 via a slip clutch in the form of a ratchet connection in both a clockwise and counterclockwise direction, wherein it can assume a plurality of predefined detent positions. This mechanism will be explained below. Inside the dosing sleeve 60, an inner ring 250 is arranged and rigidly connected to the dosing sleeve 60. The inner ring 250 has a plurality of longitudinal grooves in its radial inner surface. In the distal direction of the inner ring 250, a ratchet ring 260 is held axially displaceably, but secured against rotation, in the dosing sleeve 60. The ratchet ring 260 is formed jagged on its distal end, complementary to the teeth 244 of the serrated proximal end face of the stop sleeve 240, so that teeth of the ratchet ring 260 can engage in recesses in the end face of the stop sleeve 240 and vice versa. The ratchet ring 260 is axially displaceable between the distal end surface of the inner ring 250 and the serrated proximal end face of the stop sleeve 240 by a certain amount. The amount by which an axial displacement is possible is at least so great that the serrated end faces of the ratchet ring 260 and the stop sleeve 240 can disengage. The ratchet ring 260 is resiliently urged against the stop sleeve 240 by a spring force. For this purpose, a plurality of axial bores 251 in the form of blind holes are provided in the inner ring 250. In at least one of these bores, preferably in at least two bores at a uniform distance along the circumference of the ring, compression-loaded coil springs 252 are used. The coil springs 252 press the ratchet ring elastically against the stop sleeve.

In the rest position, the ratchet ring 260 with its serrated end face is in engagement with the serrated end face of the stop sleeve 240. As a result, the ratchet ring and the dosing sleeve 60 connected to it assume one of several defined angular positions about the longitudinal axis. Upon rotation of the metering sleeve 60 relative to the housing sleeve 20, the teeth of the ratchet ring 260 and the stop sleeve 240 slide against each other against the axial spring force of the coil springs 252 until they disengage and engage again in the next defined angular position. In this way creates a by turning with a sufficient torque spring-releasable locking connection in several predefined angular positions the metering sleeve 60 relative to the housing sleeve 20. This mechanism may also be referred to as a double slip clutch.

By turning the metering sleeve 60 clockwise, the coil spring 310 can be stretched, which is indicated in Fig. 3. The coil spring 310 has a plurality of spring coils which rotate about the longitudinal axis and are arranged one above the other radially to the longitudinal axis. The inner end of the coil spring 310 is fastened to a spring holding region 311 of the coupling shaft 230, which is particularly clearly visible in FIG. 12C. The outer end of the coil spring 310 is attached to a spring sleeve 320, which is rotatably held in the stop sleeve 240.

On the coupling shaft 230, a clutch plate 270 is mounted and secured by a pin 271 in the transverse bore 232 of the coupling shaft 230 against rotation and displacement. The clutch disc 270 has a plurality of longitudinal ribs on its outer peripheral surface. In the position of Fig. 3, these longitudinal ribs engage in the complementary longitudinal grooves on the inside of the inner ring 250, but can be brought out of engagement by an axial displacement.

The metering sleeve 60 has an axial passage opening, in which the push button 80 is arranged axially displaceable. The push button 80 is with a plurality of radially resilient arms 81 rotatably and non-displaced clicked on the proximal end 233 of the coupling shaft 230. He pushes with its distal end against a proximal end face of the clutch disc 270. Inside the push button 80 is a coil spring 82 which rests with its proximal end on the inner end face of the push button and presses with its distal end against a support ring 83. The support ring 83 has on its outer circumferential surface longitudinal ribs which are guided in corresponding longitudinal grooves in the inner jacket surface of the push button 80. As a result, the support ring 83 in the push button 80 rotatably and axially displaceable. At its distal end side of the support ring 83rd formed flat jagged. The proximal end face of the clutch disc 270 is designed to be jagged in a complementary manner, so that the support ring 83 is axially toothed with the clutch disc 270. When dispensing the drug, the clutch disc 270 rotates relative to the support ring 83. The serrated surfaces slide on each other, so that the teeth alternately into and out of engagement. This produces a distinctive clicking sound that indicates to the user that an administration is taking place. The toothing of the support ring 83 and the clutch disc 270 is preferably designed such that each click corresponds to just one unit (or a predetermined multiple of a unit) of the administered medicament.

seal

The entire mechanism for setting the dose and the distribution is splash-proof housed in the housing sleeve 20. For this purpose, a total of four seals D1, D2, D3 and D4 are present. The seal D1 comprises a sealing ring, which bears sealingly between the mechanism holder 150 and the bayonet sleeve 160. The mechanism holder 150 is immovable and tightly mounted in the housing 2, while the bayonet sleeve 160 relative to the mechanism holder 160 is both displaceable and rotatable and is sealed via the seal D1 relative to the housing. The seal D2 comprises a further, here flat-shaped sealing ring which bears sealingly between the bayonet sleeve 160 and the smooth outer side of the feed sleeve 90. Furthermore, the feed flange 100 is arranged tightly on the feed sleeve 90. In this way, the region of the injection device located proximally from the bayonet sleeve 160, including the interior of the advancing sleeve 90, is completely sealed against the area lying distally therefrom. If liquids should reach this distal area, eg due to a breakage of the medicament bundle 40, they can not penetrate into the difficult mechanics and cause them to become dirty or stick together. The other two seals are located at the proximal end of the injection device. The seal D3 comprises a sealing ring which bears sealingly between the dosing sleeve 60 and the stop sleeve 240. The stop sleeve 240 is immovable and tightly mounted in the housing sleeve 20, while the dosing sleeve 60 against the stop sleeve 240 is rotatable. The seal D4 comprises a further sealing ring, which rests sealingly between the dosing sleeve 60 and the push button 80. In addition, a transparent window cover 22 is placed liquid-tight on the window 21. As a result, the entire mechanism, which is limited to the outside through the housing sleeve 20, the metering sleeve 60 and the push button 80, also completely sealed to the outside and so completely protected against the ingress of liquids. Even a rain shower or accidentally overturned by the user glass of water can therefore not harm the injection device.

In particular, the seal to the feed sleeve out is preferably designed such that it acts as a scraper, similar to a windscreen wiper in the car. For this purpose, at least to the distal side preferably a smallest possible contact angle between the surfaces of the sealing element and the feed sleeve. This can be below 90 degrees.

Instead of conventional seals or in addition thereto, the parts to be sealed against each other may have a hydrophobic surface, in particular be formed from or coated with a hydrophobic material. A hydrophobic surface prevents the parts from being wetted. As a result, water droplets emit water and creep of liquids through gaps between the parts to be sealed due to capillary effect is effectively prevented. The provided with a hydrophobic surface, against each other to be sealed parts can therefore be arranged at a certain distance (gap) to each other without the sealing effect is lost ("virtual Ie seal").

By a hydrophobic surface is meant here a surface for the contact angle of a water droplet is at least 90 degrees, preferably at least 110 degrees. The contact angle is the angle between the surface normals of the water droplet and the respective surface at the contact point. Examples of materials having hydrophobic properties are PTFE (polytetrafluoroethylene) or PVDF (polyvinylidene fluoride). Many other materials, especially for thin coatings in the range of a few micrometers, are known.

In experiments, various pins and a sleeve were nanotechnologically provided with a hydrophobic coating. 20 pins with outer diameters of 10.0 to 11.9 mm in increments of 0.1 mm were examined. The pins were placed centrally in a sleeve with 12 mm inner diameter, which corresponds to gap thicknesses of 0.05 mm to 1.0 mm in increments of 0.05 mm. The interior of the sleeve was then charged with water. A sealing effect was observed up to a gap thickness of about 0.5 mm. With mutual rotation between pin and sleeve, a sealing effect was observed up to a gap thickness of about 0.25 mm.

To improve the sealing effect, the surfaces may be micro- or nanostructured, i. be provided with structures whose dimensions are in the nanometer to micrometer range. These structures may have a preferred direction to inhibit the flow of liquids on the surface in one direction. Thus, e.g. Shed be provided.

clutches

In the following, the mode of operation of the injection device will now be explained. Reference is first made to FIG. 16, in which the injection device is shown in its initial position before the first use. The above-explained mechanism for setting and dispensing a dose has three clutches K1, K2, and K3 for the transmission of torques. each These couplings can be brought by an axial movement of two components against each other in and out of engagement.

The coupling K1 is formed by the longitudinal grooves on the inner surface of the axial flange 235 of the coupling shaft 230 as a coupling input member in cooperation with the longitudinal ribs 122 on the outside of the coupling sleeve 120 (see Fig. 5) as a coupling output member. In the position of Fig. 16, this coupling is disengaged, that is, the teeth formed by the longitudinal grooves and longitudinal ribs is disengaged. The coupling K1 can be coupled by an axial displacement of the coupling shaft 230 in the distal direction.

The coupling K2 is formed by the longitudinal grooves in the radial inner surface of the inner ring 250 as a coupling input member in cooperation with the longitudinal ribs on the radial outer surface of the clutch disc 270 as a coupling output member. In the position of Fig. 16, this coupling is engaged, that is, the teeth formed by the longitudinal grooves and longitudinal ribs are engaged. The clutch K2 can be disengaged by an axial displacement of the clutch disc 270 in the distal direction.

The coupling K3 is formed by the longitudinal ribs on the outside of the outer annular flange 282 of the locking sleeve 280 as a coupling input member in cooperation with the longitudinal grooves 158 on the inner surface of the mechanism holder 150 as a coupling output member. In the position of FIG. 13, this coupling is engaged. It can be disengaged by an axial displacement of the locking sleeve 280 in the distal direction.

All three clutches Ki, K2 and K3 can be engaged or disengaged by the push button 80 is moved far enough axially. In doing so, a certain order is kept. When pressing the push button 80, the clutch disc 270 and the coupling shaft 230 fixedly connected to it are displaced in the distal direction. First comes the clutch K1 in Engaging, that is, the coupling shaft is coupled for torque transmission with the coupling sleeve 120. At the same time, the coupling shaft 230 advances the transmission sleeve 210 in the distal direction. This takes the locking sleeve 280 in the distal direction, whereby the clutch spring 290 is compressed. When the clutch K1 first engages, the locking sleeve 280 has not advanced sufficiently far to disengage from the mechanism holder 250 with its outer annular flange 282. The clutch K3 is thus initially still engaged. The same applies to the clutch K2: The clutch disc 270 is initially still in engagement with the inner ring 250. First of all, therefore, all three clutches are now engaged. When the push button 80 is further inserted, next the clutch K2 disengaged. In a further further insertion, finally, the clutch K3 also disengaged. The following sequence is therefore adhered to: • Initial state: K1 disengaged, K2 and K3 engaged.

• Pressing the push button 80: K1 engages, then K2 disengages, then K3 disengages.

FIG. 19, which will be described in more detail later, shows the injection device when the push-button 80 is fully depressed. The clutch K1 is now engaged while the clutches K2 and K3 are disengaged.

When the push button 80 is released, the engagement of the clutches takes place in the reverse order. The clutch spring 290 presses the locking sleeve 280, the transmission sleeve 210, the clutch shaft 230, the clutch disc 270 and the push button 80 back into the distal starting position.

The couplings K1, K2 and K3 and the ratchet connection allow the targeted transmission of torque between five functionally independent units. A first unit is formed by the housing sleeve 20, the mechanism holder 150, the stop sleeve 240 and the spring ring 320. These Unit may be functionally understood as a holding device or a housing in an expanded sense. It represents the stationary reference system for all movements.

A second unit is formed by the metering sleeve 60, the inner ring 250 and the ratcheting ring 260. It can be functionally understood as a rotatable metering device. This metering device is detachable via the ratchet connection on the housing, but held torque-resistant up to a certain value.

A third unit is formed by the clutch disc 270, the clutch shaft 230 and the transmission sleeve 210, which are all rigidly connected to each other, and by the associated coil spring 310, which acts as the actual drive element. This unit can be understood as a drive device. The rotational movement of the drive device is limited by two limiting elements, both of which are guided on the transmission device. The first limiting element is formed by the display drum 70 which limits the range of movement of the drive device in both directions, a metering direction and a correcting and dispensing direction. The second limiting element is formed by the dose-limiting ring 220 which limits the range of movement of the drive device at least in one direction, the metering direction, independently of the first limiting element. The drive device can be detachably coupled in a rotationally fixed manner to the metering device by means of the clutch K2, which makes it possible to tension the drive element in the form of the spiral spring 310.

A fourth unit comprises the coupling sleeve 120 and the threaded rod 180, which form a rigid unit, the elements on which these parts are mounted, namely the guide sleeve 110, the bearing holder 130 and the ball bearing rings 140, and the feed sleeve 90. This unit represents a conveying device, the rotational movement of an input member in the form of the coupling sleeve 120 in a feed of the conveying element in the form of the feed sleeve 90 converts. Your input member is releasably rotatably coupled by the clutch K1 with the drive device. In addition, it is releasably rotatably coupled via the clutch K3 with the holding device (ie the housing).

Furthermore, a Auslöseeinπchtung is present, which primarily comprises the push button 80 and is used to operate the clutches K1 to K3.

functionality

The injection device is operated as follows. Starting from the starting position of FIG. 16, a dose to be administered is initially set. For this purpose, the dosing sleeve 60 is rotated clockwise. The dosing sleeve takes over the clutch K2 the clutch disc 270 and the clutch shaft 230 with. As a result, the coil spring 310 is wound up. The resulting torque is maintained by the ratchet connection between the co-rotating ratchet ring 260 and the stationary stop sleeve 240. By the rotation of the coupling shaft 230 and the transmission sleeve 210 and the display drum 70 guided thereon are also rotated. The display drum 70 is also displaced axially in the proximal direction because of their thread guide on the mechanism holder 150, thus performs a total of a screw movement in the proximal direction. As a result, marks on the surface of the display drum 70 pass under the window 21 and indicate the currently set dose. Furthermore, due to its threaded engagement with the interior of the transmission sleeve 210 and due to its rotationally secured arrangement on the coupling sleeve 120, the dose limiting ring 220 is displaced in the proximal direction.

Fig. 17 shows the injection device after half the maximum single dose has been set. The display drum has moved halfway between its distal and proximal end positions. In addition, the dose limiting ring 220 has moved in the proximal direction by an amount proportional to the set single dose. The rotation of the metering sleeve 60 in the clockwise direction is limited on the one hand by the maximum range of movement of the display drum 70, on the other hand by the maximum range of movement of the dose limiting ring 220. The display drum 70 comes after a predetermined number of revolutions of the dosing sleeve 60 with its proximal radial stop against the stop sleeve 240, unless the rotation of the dosing sleeve 60 has not previously been limited by the dose limiting ring 220, as described in more detail below. As a result, further rotation of the dosing sleeve 60 is no longer possible. This position corresponds to the maximum adjustable single dose. This situation is shown in FIG.

If the set dose is to be corrected, that is to say reduced, then the metering sleeve 60 can be turned counterclockwise against the force of the ratchet connection. Since the ratchet in this direction additionally has to absorb the torque of the coil spring 310, the ratchet connection is designed asymmetrically: The frontal toothing has a larger pitch angle on that side which is loaded by a torque acting counterclockwise on the dosing sleeve on the side which is loaded at a torque in a clockwise direction (see the configuration of the teeth 244 in Fig. 14). In this case, the absolute angle of the angle between the respective flank of a tooth on the end face of the ratchet ring 260 or on the end face of the stop sleeve 240 and a cross-sectional area through the injector is understood as the pitch angle.

The distribution of the dose thus set takes place by pressing the push button 80. As a result, first the clutch K1 is engaged. This results in a rotationally fixed connection between the coupling shaft 230 on the one hand and the coupling sleeve 120 and the threaded rod 180 rigidly connected thereto on the other hand. Now all three clutches K1, K2 and K3 are engaged. Upon further depression of the push button 80, the clutch K2 disengages. As a result, the rotationally fixed connection between the metering 60 on the one hand and the coupling shaft 230 with the now coupled coupling sleeve 120 and threaded rod 180 on the other hand repealed. This causes the ratchet connection no longer absorbs the torque of the coil spring 310. The system is still rotatably held on the clutch K3 in the mechanism holder 150 and thus in the housing sleeve 20. When the push button 80 is pressed further still, the clutch K3 also disengages. At this moment, the torque of the coil spring 310 is released and acts on the threaded rod 190 via the coupling shaft 230 and the coupling sleeve 120. As a result, these parts are set in a counterclockwise rotation. Through its threaded engagement with the threaded rod 190, the feed sleeve 90 undergoes an axial displacement in the distal direction. About the feed flange 100, the feed sleeve pushes the plug 41 in the carpule 40 before. In this way, the drug is released.

During dispensing, significant axial forces are applied to the advancement sleeve 90: The torque of the coil spring 310 is converted to a force in the advancing direction that drives the plug 41 in the carpule 40. On the other hand, these forces are absorbed by the ball bearings between the coupling sleeve 120 on the one hand and the guide sleeve 110 and the bearing holder 130 in a low-friction manner, so that frictional opposing forces which might reduce the driving torque are minimized.

During dispensing, the display drum 70 is again entrained counterclockwise by the rotation of the transmission sleeve 210, and is thereby again distally moved because of its threaded engagement with the stationary mechanism holder 150 until it returns to its distal starting position. In this position, it is prevented by a radial stop on further rotation, whereby the distribution is terminated. After the end of the distribution, the display drum again displays the dose "zero".

The payout can be interrupted at any time by the push button 80 is released. As a result, the clutches K3 and K2 engage again, and the clutch K1 disengages again. The display drum 70 indicates the remaining remaining dose that is still being dispensed when the push button is pressed again, thereby continuing the dispensing.

The dose-limiting ring 220 maintains its axial position during dispensing, as the transmission sleeve 210 and the coupling sleeve 120, between which the dose-limiting ring 220 is located, rotate synchronously.

After the end of the distribution, the injection device is ready for the next injection process. Compared to FIG. 16, however, two components have changed their position: on the one hand, the feed sleeve 90 has migrated in the distal direction in accordance with the distributed dose. On the other hand, the dose-limiting ring 220 has also migrated by a proportional amount in the proximal direction. Apart from this, the state after the end of the injection corresponds to the initial state of FIG. 16. Thus, with each further injection, the advancement sleeve 90 moves further in the distal direction, while the dose-limiting ring 220 moves in the proximal direction. This is illustrated in FIG. 19, which depicts the injection device, after first administering a first dose equal to half the maximum single dose, and then again setting a dosage with the dose tube which in turn corresponds to half the maximum single dose. The display drum now displays again, as in FIG. 15, half the maximum individual dose, while the dose-limiting ring 220 now occupies a position in the transmission sleeve 210 which is the sum of the previously set doses, in this case twice the maximum single dose. equivalent.

The maximum axial travel by which the dose-limiting ring 220 can travel in the proximal direction in the transfer sleeve corresponds to the contents of a completely filled carpule. As soon as the sum of the set doses on the dosing sleeve corresponds to the carpule contents, the dose-limiting ring 220 reaches its proximal end position and, with its radial stop, abuts the axial annular flange 235 of the coupling shaft 230, as shown in FIG Fig. 12A is shown. As a result, the metering sleeve 60 is prevented from further rotating in a clockwise direction. It can therefore be set no larger dose than the dose corresponding to the remaining amount of the drug in the carpule. Fig. 20 shows this situation, in which no more metering is possible, although the display drum is in the distal starting position, ie the zero position. Accordingly, the feed sleeve 90 has reached its distal end position, so it is maximally extended.

Karpulenwechsel

To replace the carpule, the cartridge sleeve 30 is released against the elastic resistance of the bayonet spring 170 from the mechanism holder 150 and out through the corresponding guide slot 156 in the mechanism holder out. As a result, the bayonet sleeve 160 is forcibly also twisted along its own, parallel guide slot 155 and simultaneously displaced in the distal direction. As a result, the guide sleeve 110 is pulled in the distal direction. As a result, all the axially associated moving parts, in particular the coupling sleeve 120, the threaded rod 190, the locking sleeve 280, the transmission sleeve 210, the coupling shaft 230, the clutch disc 270 and the push button 80 also migrate in the distal direction. In particular, the push button 80 is thus drawn into the dosing sleeve 60 and thus indicates that the injection device is not ready for operation.

By this axial displacement of the various parts of the mechanism, the clutches K2 and K3 come out of engagement, while K1 was already out of engagement. If a dose has been set before the cartridge has been changed but has not been administered, the correspondingly wound coil spring 310 then rotates the clutch shaft 230 and the associated transmission sleeve 210 in a counterclockwise direction until the display drum 70 has reached its distal end position and prevented by its radial stop on the mechanism holder 150 further turning back. On in this way, the display drum 70 is returned to its distal home position, the zero position. So there is an automatic reset of the dose display to zero.

If there was still a residual amount of the drug in the carpule 40 before the carpule change, then the feed sleeve 90 was not yet maximally extended before the carpule change, so had not yet reached its distal end position. When removing the carpule sleeve 30, the coil spring 190 now presses the guide needle 200, the feed flange 100 and the feed sleeve 90 in the distal direction. As a result, the threaded rod 180 is rotated via its screw connection with the interior of the feed sleeve 90 in rotation. In this case, the threaded rod 180 takes in particular the coupling sleeve 120 and the dose-limiting ring 220. The dose limiting ring 220 is displaced in this rotation by its threaded engagement with the transmission sleeve 210 in its proximal end position. Once the dose limiting ring 220 has reached this starting position, it prevents further rotation of the coupling sleeve 120 and the threaded rod 180, so that no further extension of the feed sleeve 90 is possible. The feed sleeve 90 has now reached its distal end position. This situation is shown in FIG. Overall, so now is the display drum 70 in the neutral position, the dose limiting ring 220 in the proximal end position and the feed sleeve 90 in its distal end position.

Now, a new carpule 40 is inserted into the cartridge case 30, and the cartridge case 30 with the carpule 40 received therein is axially guided in the proximal direction against the housing sleeve 20. Initially, the plug 41 of the carpule presses the feed flange 100 and the feed sleeve 90 against the force of the coil spring 190 in the proximal direction. As a result, in turn, the threaded rod 180 is rotated. The threaded rod again takes the coupling sleeve 120 and the dose limiting ring 220 with it. As a result, the dose-limiting ring, due to its threaded engagement with the transmission sleeve 210 in the distal direction, ie in the direction of his Starting position shifted. The amount by which it is displaced in this direction corresponds to the dose present in the carpule 40. For a fully filled carpule, the dose-limiting ring 220 migrates to its distal starting position. The cartridge sleeve 30 is then inserted into the mechanism holder 150, with the radial pins 36 of the cartridge sleeve 30 again engaging in the guide slots 156 in the mechanism holder 150 (compare FIGS. 1 and 3). As a result of the positive guidance of the cartridge sleeve 30 when it is inserted into the mechanism holder 150, in turn the bayonet sleeve 160 is forced to follow the movement of the cartridge sleeve 30 in the corresponding guide slots. The bayonet sleeve 160 is thereby returned to its proximal end position, in which it is releasably locked by the bayonet disc 170 (see Figures 8 to 10). The injection device is now back in the starting position of Fig. 16 and is available after screwing a new needle holder 31 for a new sequence of administrations available.

Second embodiment

FIG. 21 shows as a variant a second embodiment of the injection device according to the invention. The operation is substantially the same as in the first embodiment. Like-acting parts are therefore designated by the same reference numerals as in the first embodiment. In the following, only the essential differences will be discussed.

In the second embodiment, the stop sleeve 240 omitted. Their function is taken over by the correspondingly elongated housing sleeve 20.

The drive device, which is formed in the first embodiment, apart from the coil spring 310, from the clutch disc 270, clutch shaft 230 and transfer sleeve 210 is here formed by other parts, namely by a connecting shaft 400 (integrally formed thereon with clutch disc 401) , a first transmission closed at the proximal end, transmission sleeve 410 and a distal thereto second transmission sleeve 420. These three parts are in turn rigidly interconnected.

While in the first embodiment, the display drum served not only to display the set dose, but also to limit the maximum adjustable single dose in the metering direction and to limit the movement in the discharge direction, the latter function is adopted by a second dose limiting ring 430 in the second embodiment , This is rotatably, but axially displaceably guided in the housing sleeve 20. With an internal thread, it runs on a corresponding external thread of the first transmission sleeve 410. Its axial movement is limited by two radial stops between a distal starting position, which corresponds to the zero position, and a proximal end position, which corresponds to the maximum adjustable dose. In this way, it takes over the abutment functions of the display drum according to the first embodiment.

The display drum 70 is guided in the second embodiment via a rigidly connected to it driving sleeve 440 axially and rotatably on the second transmission sleeve 420. Their operation is otherwise the same as in the first embodiment.

Apart from these differences, structure and operation of the injection device are substantially the same as in the first embodiment.

Other variants

The differences between the first and the second embodiment show that the functions of the injection device according to the invention can be achieved in many ways and the invention is in no way limited to the exemplary embodiments presented above. Various other modifications are possible. These may be caused in particular by manufacturing requirements. LIST OF REFERENCE NUMBERS

R drug reservoir

D1 seal

D2 seal

D3 seal

D4 seal

K1 first clutch

K2 second clutch

K3 third clutch

10 protective sleeve

11 retaining ring

12 detent arm

20 housing sleeve

21 windows

22 window cover

30 cartridge case

31 needle holder

32 hollow needle

33 Needle protection cover

34 viewing window

35 locking area

36 cones

40 carpule

41 plugs

50 protective cap

60 dosing sleeve

61 spring washer

70 display drum

72 annular area

73 Radial stop 80 push button

81 arm

82 coil spring

83 support ring

90 feed sleeve

91 guide cams

92 internal thread

100 feed flange

110 guide sleeve

111 flange

112 bore

120 coupling sleeve

121 sleeve body

122 longitudinal rib

123 thickening

124 flange

130 storage holders

132 shoulder

140 ball bearing ring

141 Bearing ball

150 mechanism holder

151 distal section

152 proximal section

153 level

154 longitudinal slot

155 guide slot

156 guide slot

157 external thread

158 longitudinal groove

159 radial stop

160 bayonet sleeve

161 ring flange 162 arm

163 opening

170 bayonet spring

171 basic body

172 lead

173 tongue

180 external threaded rod

181 cross bolts

190 coil spring

200 guide needle

201 thickening

202 cones

210 transmission sleeve

211 female thread

212 longitudinal rib

213 ring flange

220 dose limiting ring

221 external thread

222 longitudinal groove

223 radial stop

230 coupling shaft

231 axis

232 cross bore

233 proximal end

234 flange

235 ring flange

236 Radial stop

237 bore

238 longitudinal groove

240 stop sleeve

242 hole

243 radial stop 244 tooth

250 inner ring

251 bore

252 coil spring

260 ratchet ring

270 clutch disc

271 pen

280 locking sleeve

281 main body

282 arm

283 flange area

284 longitudinal groove

290 clutch spring

300 support ring

310 spiral spring

311 spring holding area

320 spring sleeve

400 connecting shaft

401 clutch disc

410 first transmission sleeve

420 second transmission sleeve

430 second dose limiting ring

440 driving sleeve

Claims

claims

1. Device for administering a fluid product,

Comprising a housing (20) having a conveying element (90) for conveying the product from a reservoir (40), wherein the conveying element (90) is movable relative to the housing (20) along a feed axis, and wherein the conveying element (90) an internal thread whose threaded axis runs along the feed axis, and with a threaded element (180) with an external thread which engages with the internal thread of the conveyor element, wherein the threaded element (180) can be fixed relative to the housing (20) along the feed axis and in a rotational movement about the feed axis is displaceable in order to advance the conveying element (90) along the feed axis, characterized in that the conveying element (90) relative to the housing (20) is arranged rotationally fixed.

The apparatus of claim 1, further comprising a container holder (30) detachable from the housing (20) for holding a reservoir (R, 40) with the product, wherein in a condition where the container holder is detached from the housing, the threaded member (180) relative to the housing is rotatable such that the conveying element (90) in this state by a purely axial displacement in the proximal direction is inserted into the housing.

A device according to claim 1 or 2, wherein the device comprises a spring element (190) arranged to generate a spring force which acts on the conveyor element (90) opposite the housing (20) along the feed axis in a distal direction acts.

4. Apparatus according to claim 3, wherein the spring element (190) in the interior the threaded element (180) is arranged.

5. Apparatus according to claim 4, wherein the spring element (190) is designed as a helical spring which is guided on a guide needle (200).

6. Device according to one of the preceding claims, wherein the conveying element (90) relative to the housing (20) along the feed axis between a proximal starting position and a distal end position is movable and has a substantially smooth outer wall portion whose length at least the distance between the distal end position and the proximal starting position corresponds.

7. Device according to one of the preceding claims,

Wherein the conveying element (90) is radially at least partially surrounded by a guide sleeve (110) having a proximal and a distal end, wherein the guide sleeve (110) is rotatably connected to the housing (20) near its distal end, and wherein the conveying element (90) rotationally fixed along the feed axis in the guide sleeve (110) is guided, and

Wherein the device comprises an outer sleeve (120) having proximal and distal ends at least partially surrounding the guide sleeve (110) which is connected near its proximal end to the threaded member (180) and which is proximal to its distal end End rotatably and non-displaced relative to the guide sleeve (110) is guided.

8. The apparatus of claim 7, wherein the conveying element (90) along the feed axis between a proximal starting position and a distal end position is movable, and wherein the guide sleeve

(110) has a length which is at least the distance between the corresponds to the distal and the proximal end position of the conveying element (90).

9. Apparatus according to claim 7 or 8, wherein the conveying element (90) in the region of its proximal end with the interior of the guide sleeve

(110) is in a rotationally fixed and displaceable engagement.

10. Apparatus according to claim 9, wherein in the region of the proximal end of the conveying element (90) a radially outwardly from an outer peripheral surface of the conveying element (90) projecting engagement structure is formed, which with a complementary structure on an inner circumferential surface of the guide sleeve (110). interacts.

11. The apparatus of claim 10, wherein the engagement structure comprises a plurality of longitudinal ribs and the complementary structure comprises a

Comprises a plurality of longitudinal grooves.

12. Device for administering a fluid product,

Comprising a housing (20) and a conveying element (90) for conveying the product from a reservoir (40),

Wherein the conveying element (90) is movable relative to the housing (20) along a feed axis between a proximal starting position and a distal end position,

• with a drive device (310) for generating a rotational movement relative to the housing, wherein the rotational movement of a

Feed movement of the conveying element (90) causes along the feed axis, characterized in that the conveying element (90) has a substantially smooth outer wall portion whose length corresponds at least to the distance between the distal end position and the proximal starting position.

13. The apparatus of claim 12, wherein the conveying element (90) relative to the housing (20) is guided rotatably.

14. The device according to claim 12 or 13, which further comprises a housing detachable container holder (30) for holding a reservoir (R,

40) with the product, wherein the conveying element (90) is insertable by a purely axial displacement in the housing when the container holder (30) from the housing (20) is released.

15. Device according to one of claims 12 to 14, wherein the device comprises a spring element (190) which is arranged such that it generates a spring force which on the conveying element (90) relative to the housing (20) along the feed axis in a distal direction acts.

16. Device according to one of the preceding claims, wherein the conveying element (90) relative to the housing (20) is guided liquid-tight.

17. The apparatus of claim 16, wherein the conveying element (90) has a substantially smooth, cylindrical outer wall portion which is surrounded by at least one annular sealing element (D2).

18. The apparatus of claim 17, wherein the at least one annular sealing element (D2) comprises at least one circumferential sealing lip, which rests on the cylindrical outer wall region of the conveying element.

19. Device according to one of the preceding claims, wherein the threaded element (180) is designed as an external threaded rod.

20. Device according to one of the preceding claims, wherein the Conveying element (90) relative to the housing (20) along the feed axis between a proximal starting position and a distal end position is movable and the conveying element with respect to the positions defined by these positions has a proximal end and a distal end, and wherein the internal thread only in one area is arranged near the proximal end of the conveying element.